Integrated circuits, including a semiconductor die such as charge-coupled-devices (CCD) and complementary metal oxide semiconductor (CMOS) sensors have commonly been used in photo-imaging applications. Such sensors typically contain thousands of pixel cells in a pixel array on a single chip. Pixel cells convert light into an electrical signal that can then be stored and recalled by an electrical device such as, for example, a processor.
Semiconductor dies typically are packaged and inserted into imaging devices such as, for example, digital cameras. FIG. 1 illustrates a conventional image sensor module 2, shown in an exploded perspective view. Module 2 includes a semiconductor die 4 disposed on a cushion 6 and having series of bump pad connectors 8 located adjacent the four edges of the top surface of the semiconductor die 4. Semiconductor die 4 includes a pixel array (not shown). Anisotropic conductive film (ACF) 10 connects flex tape 12 to die 4 and connectors 8. Flex tape 12 contains electrical traces that link to a connector 14, and has an opening 16 through which light travels to the pixel array. A stiffener 18 provides additional support to the module 2. An infrared (IR) filter 20, aligned in the optical path between the pixel array and a lens assembly 22, is adhered onto the flex tape 12. The lens assembly 22 includes a housing 24 supporting a lens barrel 26 containing a lens system for focusing light onto the pixel array.
In operation, light radiation enters the lens barrel 26 of the module 2. Harmful IR radiation is filtered out by the IR filter 20. Light radiation incident on the pixel array of semiconductor die 4 is converted to electrical output signals by the circuitry on semiconductor die 4. The electrical traces in flex tape 12 conduct the electrical output signals from the semiconductor die 4 to external circuitry (not shown) connected to connector 14. The external circuitry may include processing circuits for storing, compressing, manipulating, or displaying an acquired image.
While the package illustrated in FIG. 1 works well, the assembly process includes several steps, and requires forming flex tape 12 with opening 16. Also, the form factor of module 2 is increased in width and length by the placement of bond pads 8. Thus, a semiconductor die package that has a smaller form factor, and which requires fewer assembly steps, is desired.